When I was four, my mom was taking night classes at Philadelphia Community College to become a registered nurse. Sometimes my dad would let me stay up and wait for her to come home, and sometimes I snuck out of bed and waited without him knowning. I wasn't a kid who liked going to bed early.

So one night, my mom came home, and I was playing on the couch--namely, I was sitting on one of the arms, my feet on the cusions of the couch--a precarious position. I don't know how many times my parents told me not to sit like that, but I've never been good at doing what I'm told.

Well, naturally, this was the night when I finally fell. Back I went, head first into wall. I put a good-sized dent in the plaster, about a half an inch thick. I don't remember it happening. I vaugely remember my parents taking me to Children's Hospital, but really, it's a blur, except for being really hungry for french fries at the McDonalds in the hospital.

Fast forward about a year. I was rollerskating--old Fischer-Price rollerskates that you slipped your shoes into, instead of real rollerskates like the older kids. The wheels are spaced farther apart, making it more difficult to lose your balance, or so the theory goes. Well, I'm skating and I feel myself begin to fall backwards. Naturually, I reached my hand out to the wall next to me. And, naturally, I grabbed the one loose brick. So down I went, the back of my head hitting the pavement, the top of my head being hit with the brick.

That year, I started having this problem. I can be sitting, watching tv, basically doing nothing special. Someone might be talking to me, having a normal conversation. And suddenly, I can't remember who they are. I can't remember who I am, either. It usually only lasts about thirty seconds, but they are some of the worst seconds in my life.

I sit there, perfectly normal. Randomly, it's like someone hit the reset button. Like someone wiped my hard drive. But like all hard drives, the information isn't really gone, just hard to recover. It's a jolt, a literal though physically small jolt--I feel dizzy, sometimes nauseous, sometimes nothing at all. But always, I forget my entire emotional history.

My uncle died when I was 15. I remember sitting in the basement, watching tv while my mom talked to me about it. Suddenly, it came on me, and I didn't recognize her at all. I had no idea who she was, who I was, what I was doing there. After about five seconds like this, I'm able to tell myself--"You're Mary. This is your mom. This is your house." But all emotional memory is gone--I don't know her as anything other than a fact that doesn't feel at all attached to me. After a minute or so of feeling this way, it eventually returns and I'm OK.

My husband and I were in the supermarket, standing at the deli counter. And suddenly, I couldn't remember who he was. Our entire past (admittedly only three years) was gone. Who I am was gone. He knows, he understands.

For years I kept it a secret. I tried telling a few therapists about it, but they dismissed it--I suppose they just didn't know what it was or what to tell me.

There is no way to explain how terrifying it is to experience this fairly frequently. It's never for a long duration--probably the most was about a minute and a half. I spent that minute staring at myself in the mirror, waiting for what I saw to make sense.

What hurts, what scares me, is that every couple of weeks, (though sometimes I can go for months) I forget everything.

I forget my life.

I forget my family.

But the weird thing is, I also forget every stupid, embarrassing, damning thing I've ever done. I forget every argument, every petty hatred, every insult I've received and given. I forget the breakups, I forget the carjacking, I forget the reasons I drink too much and can be emotionally distant. Because at that moment, there are no emotions, there is no past.

For those few seconds, I'm free.